Table 1 Endoscopic score of activity modified from Rutgeerts and colleagues.¹⁰.

Grade	Endoscopic findings
0a	No lesions in the distal ileum
0b	Stenosis without inflammation
1	⩽5 aphthous lesions
2	>5 aphthous lesions with normal mucosa between the lesions, or skip areas of larger lesions confined to the ileocolonic anastomosis
3	Diffuse aphthous ileitis with diffusely inflamed mucosa
4	Diffuse inflammation with larger ulcers
5	Ulcerated stenosis